The woman’s case, published January 30 in The New England Journal of Medicine, was considered the most clearly documented evidence that the novel viral infection could spread silently from asymptomatic people. Public health experts have been particularly anxious about such transmission because it could potentially ease disease spread and negate outbreak control efforts, including screening travelers for symptoms, such as fever.

“The fact that asymptomatic persons are potential sources of 2019-nCoV infection may warrant a reassessment of transmission dynamics of the current outbreak,” the authors of the NEJM article concluded.

But that conclusion now appears to be based on false information. And, while the new information on these specific cases doesn’t rule out the possibility that asymptomatic spread has occurred or is occurring in other cases, it could help ratchet down fears that asymptomatic spread is driving the now mushrooming outbreak.

Further Reading

Experts at the World Health Organization have said repeatedly that even if asymptomatic spread is occurring, it is likely a minor source of infection; coughing and sneezing people are simply much more likely to spread the virus.

Moreover, the corrected version of the NEJM article may highlight a more pressing threat to outbreak control—the fact that all five cases in the cluster were mild and unremarkable amid standard cold and flu season.

Missed signs

According to the new report in Science, the businesswoman’s 2019-nCoV infection symptoms went unrecognized because they were mild, masked by over-the-counter medications, and—most notably—the authors of the NEJM article didn’t speak with her before the article was published.

The woman, a Shanghai resident who had visited Germany from January 19 to 21, tested positive for 2019-nCoV in China on January 26. The other four cases were identified in Germany by January 28, and the case report appeared in NEJM just two days later.

Without direct communication with her prior to the publication, the NEJM article’s authors relied on the accounts of her four sickened colleagues in Germany, who said she didn’t seem sick during her visit.

Further Reading

But government health officials in Germany were later able to reach the Shanghai woman by telephone. People privy to details of the call told Science that she said she felt tired, had muscle pains, and took a fever-reducer during her visit.

Officials at the Robert Koch Institute (RKI), the German government’s public health agency, have sent a letter to NEJM informing them of the error in the article, according to an RKI spokesperson who spoke with Science.

One of the NEJM authors, Michael Hoelscher of the Ludwig-Maximilians University of Munich Medical Center, told Science that they should have been clearer about where they had gotten the information about the woman’s symptoms. “If I was writing this today, I would phrase that differently,” he said.

Another author on the article, virologist Christian Drosten of the Charité University Hospital in Berlin, said, “I feel bad about how this went, but I don’t think anybody is at fault here. Apparently, the woman could not be reached at first and people felt this had to be communicated quickly.”

Further Reading

Drosten went on to say that—despite the correction—the five cases highlight a potentially dangerous feature of this outbreak—that is, that the infection may not be very dangerous.

“There is increasingly the sense that patients may just experience mild cold symptoms, while already shedding the virus,” he said. “Those are not symptoms that lead people to stay at home.”

Circulating unknowns

Indeed, as the outbreak has continued to escalate, experts have noted that the virus appears more contagious than initially thought and that the early outbreak responses focused heavily on identifying the most severe cases, such as those involving pneumonia and respiratory distress. That focus may have potentially missed the spread of mild disease, which may be far more extensive than what is known even now.

Of the outbreak cases, a little over 200 are outside of mainland China, scattered in around two dozen countries. Some of those countries have reported limited person-to-person spread, including the United States.

Further Reading

The US Centers for Disease Control and Prevention has confirmed11 cases in the country so far, including nine travel-related cases and two cases of person-to-person transmission within the US among close contacts. The first case identified in the US, a 35-year-old in Washington state, has been released from the hospital and is now in isolation at home. The second identified case, a Chicago woman in her 60s, has been described as doing “quite well” and is primarily being hospitalized for isolation purposes.

“The look and feel of the exported cases, I think, really support the argument that there’s a lot of mild disease that is not being detected in China at the moment for the very good reason that they just can’t do it,” Dr. Allison McGeer told Stat News recently. McGeer is an infectious diseases researcher at Toronto’s Mount Sinai Hospital, who helped respond to other outbreaks of emerging coronaviruses, namely those behind SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome).

I'm trying to understand how this new information changes the risk assessment. On the one hand, it seems like this virus might be much milder in a larger number of cases than previously assumed. On the other hand, it might spread more easily as people just take a fever reducing medication and continue interacting with others.

Do we have any reliable information about the percentage of serious cases? If this is a virus that (1) is mild for a lot of people at first, so it's more easily spread, but (2) after a long incubation period, turns into a serious illness for a lot of people, then I could see how this would bode poorly for containment and overall outcomes.

Maybe, but isn't it also possible that the people who were allowed to return home to Germany were only milder cases? Without being prejudiced here, I'm assuming not, cause I'm assuming you'd want care at German, rather than Chinese hospital, if only because of the crowding.

Who doesn’t feel coldy after a flight? If I was her I would have assumed it was plane flu and got on with the work trip.

Me? Can't say I've ever felt sick as consequence of flying somewhere.

Only on one instance did I have an unrelated case of low blood sugar. Managed to stumble my way off the aircraft and find a secluded hole to hide in and wait out the cold sweats, in Dallas, at the height of the Ebola scare.

Another factor I have not seen analyzed is the effects of pre-existing air quality challenges to Chinese victims. My take is that since this is primarily a respiratory infection, poor air quality could increase the risk of serious sequelae. My experience in China was that their air quality was atrocious. Three days in Beijing, ostensibly clear days by satellite analysis but certainly not at ground level where it was only on the third day we were able to actually see a dim watered down orange glow to show where the sun was, was enough to give me the equivalent of a pack a day smoker cough.

Evolutionary pressure is all that is required, trying to read too much into "why" a virus evolves X or Y ascribes a bit too much intentionality to what is ultimately a process by which fitness is changed by random mutations.

It's gonna be super fun being Chinese with pollen allergies when Spring comes..

At least now you'll have an excuse to wear a dust mask 100% of the time.

(Note that the valves on a dust mask, like an N95 mask, make it bad at preventing people around you from getting germs *from* you. Dust masks only help you avoid getting stuff in from the outside. For that a surgeon's mask is more effective.)

This reinforces my belief that this isn’t a new nor novel disease, but an existing and already prevalent disease that had previously just been undiagnosed and mistaken as a normal cold or flu.

In other words, when mild people take medications and get on with their lives and when severe people take medications and stay home, and any deaths would be swallowed in the flu statistics. Already we’ve had 2,100 flu deaths in 2019 alone:https://www.wate.com/news/cdc-flu-death ... 20-season/

Well, as the saw cuts, you are welcome to your own opinion.

Unless you are in some position of authority, that is. Facts do count.

In this case the epidemiology -- the science -- strongly indicates 2019-nCov was first transmitted to one or more humans from one or more animals in Wuhan, China, in mid-November.

Edit2: A few days ago Dr. Jay posted How does one test for coronavirus. We do test for it, and both positive and negative results are meaningful. If a large population tests uniformly negative, it isn't there. A long-established endemic virus would be. 2019-nCov is new.

It's gonna be super fun being Chinese with pollen allergies when Spring comes..

We've already had to field questions about whether "people need to avoid the Chinese exhibit at Disneyworld because of the risk of Coronavirus" so yea, this is unmasking a TON of really pleasant xenophobia and racism. So fun.

In the US, the flu is actually close to 10% mortality among those hospitalized for it, and around 0.2-0.4% among those who bother to get a checkup. The trouble is that it's estimated less then half the people who get the flu ever seek treatment for it (in the US, no idea about China). The speculation is that this disease has similarly mild symptoms that may well be misdiagnosed or outright ignored, and the actual infection rate is far far higher than is being reported.

People shouldn't take fever reducers except to help rest more comfortably at home. Not to ensure they can still conduct their normal business. If you feel subjectively feverish (chills, flush face, etc) along with being fatigued then DON'T GO OUT! Your body is saying you are ill. In the best case, you have the flu-like illness and will make others sick.

In the worst case you have a disease like this that is both highly infectious and an appreciable death rate even with modern medical care.

In the US, the flu is actually close to 10% mortality among those hospitalized for it, and around 0.2-0.4% among those who bother to get a checkup. The trouble is that it's estimated less then half the people who get the flu ever seek treatment for it (in the US, no idea about China). The speculation is that this disease has similarly mild symptoms that may well be misdiagnosed or outright ignored, and the actual infection rate is far far higher than is being reported.

Don't forget American "work ethic". I'd rather infect, potentially mortally for 10%, any co-worker or someone I may contact at work than be perceived as a lazy worker. *achoo*

It's gonna be super fun being Chinese with pollen allergies when Spring comes..

We've already had to field questions about whether "people need to avoid the Chinese exhibit at Disneyworld because of the risk of Coronavirus" so yea, this is unmasking a TON of really pleasant xenophobia and racism. So fun.

So, lets talk about the current mortality rate a bit, because alot of the lay press seems to reference this number in a way that's a bit too etched in stone.

Realize that the mortality rate that's being published in the press and by the CDC is determined via the following calculation

(Confirmed deaths due to 2019-nCoV/Confirmed cases of 2019-nCoV) = Death rate/Case

While this seems like it should be a relatively firm number, in reality it's pretty darn squishy, primarily on the side of "Confirmed cases of 2019-nCoV". So, in a new outbreak people generally only get confirmed if they either 1. get sick and were known exposures to 2019-nCoV or 2. get REALLY sick and get admitted to the hospital, where they get tested for 2019-nCoV.

In outbreaks such as this one, the primary source of cases, especially early on tends to be from the #2 side of the spectrum. That means is that you are generally accumulating the sickest of the sickest cases, who at BASELINE are most likely sicker people and thus at higher risk of lethality from illness. It is possible, and most likely probable for that matter, that mild cases of disease NEVER GET RECORDED as confirmed cases.

So early in examination of a outbreak such as this, you can easily have an OVER estimation of lethality of a virus because your case-mix is overly representative of people with severe illness. It is entirely possible that the "average" case of 2019-nCoV is much more mild than we currently understand/expect. This may lower the actual lethality of the disease far below the current average of around 2 deaths/100 cases when all is said and done.

However, a lower lethality may be a good AND bad thing. The good is obvious, but the bad means that people who have mild illness are much more capable of spreading the virus because they don't feel that bad.

People shouldn't take fever reducers except to help rest more comfortably at home. Not to ensure they can still conduct their normal business. If you feel subjectively feverish (chills, flush face, etc) along with being fatigued then DON'T GO OUT! Your body is saying you are ill. In the best case, you have the flu-like illness and will make others sick.

In the worst case you have a disease like this that is both highly infectious and an appreciable death rate even with modern medical care.

You shouldn't even take them to feel more comfortable, IMO. Fever is part of your immune response to viruses. Why damage it?

We've already had to field questions about whether "people need to avoid the Chinese exhibit at Disneyworld because of the risk of Coronavirus"

Because Disney wants to offer the most authentic experience possible, diseases and all? I'm completely baffled at the reasoning behind that question.

I would assume that in their minds Chinese=Causing Scary Virus, so anything Chinese must put people at risk for catching the new scary disease. The same reasoning persisted about HIV and particularly LGBTQ people for WAY longer than it should have once the transmission dynamics were understood.

We've already had to field questions about whether "people need to avoid the Chinese exhibit at Disneyworld because of the risk of Coronavirus"

Because Disney wants to offer the most authentic experience possible, diseases and all? I'm completely baffled at the reasoning behind that question.

I would assume that in their minds Chinese=Causing Scary Virus, so anything Chinese must put people at risk for catching the new scary disease. The same reasoning persisted about HIV and particularly LGBTQ people for WAY longer than it should have once the transmission dynamics were understood.

So, lets talk about the current mortality rate a bit, because alot of the lay press seems to reference this number in a way that's a bit too etched in stone.

Realize that the mortality rate that's being published in the press and by the CDC is determined via the following calculation

(Confirmed deaths due to 2019-nCoV/Confirmed cases of 2019-nCoV) = Death rate/Case

While this seems like it should be a relatively firm number, in reality it's pretty darn squishy, primarily on the side of "Confirmed cases of 2019-nCoV". So, in a new outbreak people generally only get confirmed if they either 1. get sick and were known exposures to 2019-nCoV or 2. get REALLY sick and get admitted to the hospital, where they get tested for 2019-nCoV.

In outbreaks such as this one, the primary source of cases, especially early on tends to be from the #2 side of the spectrum. That means is that you are generally accumulating the sickest of the sickest cases, who at BASELINE are most likely sicker people and thus at higher risk of lethality from illness. It is possible, and most likely probable for that matter, that mild cases of disease NEVER GET RECORDED as confirmed cases.

So early in examination of a outbreak such as this, you can easily have an OVER estimation of lethality of a virus because your case-mix is overly representative of people with severe illness. It is entirely possible that the "average" case of 2019-nCoV is much more mild than we currently understand/expect. This may lower the actual lethality of the disease far below the current average of around 2 deaths/100 cases when all is said and done.

However, a lower lethality may be a good AND bad thing. The good is obvious, but the bad means that people who have mild illness are much more capable of spreading the virus because they don't feel that bad.

This is all very true, and bears repeating.

In the other direction, simply dividing by the number of confirmed cases is also incorrect due to the delay between symptoms/diagnosis and death (on the order of 5-7ish days). When many new infections are occurring, as is the case, people who will end up dying in the end contribute to the denominator of "confirmed" but not the numerator of "dead" because they haven't died yet. Unfortunately the only good report thus far that actually separates a cohort of cases by diagnosis date and breaks out the actual outcomes is the 99-case Lancet report. That had 11% of patients die, but 99 cases is really way too small.

Hopefully the two cancel each other out. If the actual CFR of 'nCoV requiring medical attention' is 10%, so long as 1 in 3 or fewer cases are actually mild (and thus don't require medical attention, and thus are missed currently), then the CFR will be well south of the 2-3% currently quoted.

In the US, the flu is actually close to 10% mortality among those hospitalized for it, and around 0.2-0.4% among those who bother to get a checkup. The trouble is that it's estimated less then half the people who get the flu ever seek treatment for it (in the US, no idea about China). The speculation is that this disease has similarly mild symptoms that may well be misdiagnosed or outright ignored, and the actual infection rate is far far higher than is being reported.

Right, but this virus has the potential to be much more dangerous than the flu. Ignore the raw numbers for a moment and look at the percentages. Yes, this virus has been contained largely to China so far, but one mutation could mean millions worldwide dead. The virus has had a 2% fatality rate.

Setting aside the "2%" number, since that was addressed before your post... on what basis do you think that one mutation could cause that? This is still a really new virus, so I'm pretty sure scientists haven't had nearly enough time to identify potential mutations that could lead to that big of a jump in fatalities. Do you just mean that hypothetically there might be a path like that? Because that's a statement that applies broadly enough that it seems sort of weird to start panicking about just this one specific instance.

The CDC does study the flu, luckily, and using some of their estimates we have a range of:

12k - 61k fatalities140k - 810k hospitalizations

We can only consider hospitalizations because those are severe enough that they would be measured vs the millions sick who don't recognize the illness or treat it with medicine and get better on their own.

TLDR: We can't assume a 1/48 kill ratio when we can't measure how many unreported illnesses there are, and the point of my numbers is to show that there is a range of fatality rates to consider. If 1 die out of 48 identified, but an additional 200 are unidentified and another 10 deaths are misattributed, you have a 11 out of 248 fatality; that puts it right around the same as the flu.